Providing for the general safety of the population and enforcing the laws to this effect have become more challenging. Rapid and accurate sampling and detection of explosives, illicit drugs, and dangerous chemicals within the environment, particularly at points of entry, such as, ports and airports, and at populated facilities, such as, public transportation, sporting arenas, and recreational facilities, is increasingly required. This analysis requires a method that can identify specific chemicals, particularly organic molecules, and unknown chemical that is not only accurate and specific, but increasingly in a manner that is rapid and can be carried out with extremely small sample sizes. For example, nearly 90% of the world's cargo is moved by sea, yet nearly 98% of the containers are not inspected because the screening methodology is lacking to identify the potential threats in an effective manner. A screening technique for these chemical dangers must be very rapid, sensitive, and easily carried out with minimal modification of the infrastructure.
Methods that have been employed for analysis are generally those that separate and detect volatile compounds, such as those using gas chromatography coupled to a mass spectrometer (GC-MS) or ion mobility spectrometry (IMS), in a variety of modes in which they can be configured to carry out reasonably rapid analysis. Particularly desirable are portable devices that can be shared between multiple sites. Additionally, simple sampling devices that can rapidly sample a gas and collect a sufficient amount of analyte are necessary to achieve a reasonable level of assurance that threats have been assessed sufficiently and fairly.
For example, the Transportation Security Administration (TSA) has mandated that every airport in the United States screen all bags for explosives. IMS is an approved screening tool, because it can detect many organic compounds in an accurate, extremely fast, and straightforward manner that is extremely sensitive while being low in cost to perform. Analysis using commercial IMS devices can be carried out in one to seven seconds. There are more than 60,000 IMS units situated throughout the world, which means that virtually all populated areas probably have an IMS device sufficiently close to a suspected site to deliver a sample rapidly to the machine.
Sampling of the air is often carried out using a solid phase microextraction (SPME) device, which provides a large surface area to absorb a target chemical rapidly with a sufficient extraction capacity and efficiency. Variations on this technology continue to be explored with the goal of enabling sampling and analysis during a sufficiently small window of time to achieve a level of comfort that the threat is discovered before that threat becomes an event.
Such sampling devices and methodology can be used for threats that are of smaller scope, but where high rapidity and accuracy is desirable. For example, detection of drugs or indicators of drugs are needed for determination that recreational drugs are not impairing an automobile driver or a technician carrying out a potentially dangerous task in construction or manufacturing. Additionally, similar sampling devices and methodology could be used for the diagnosis of diseases or assessment of an individual's health. To this end, a rapid and effective volatiles sampling device that can be readily adapted to IMS, GC-MS, or other equipment and can be employed any site and, as needed, readily transported to an analysis facility is desired.